Donald Trump and Hillary Clinton are vying for the Republican and Democratic party nominations, respectively, in the 2016 run for president. Photo Credit: AP

WASHINGTON -- The Iran nuclear deal stirred up heated debates inside and outside Congress on Wednesday as Democrat Hillary Rodham Clinton explained her support for it in a think tank speech and Republicans Donald Trump and Sen. Ted Cruz (R-Texas) attacked it at an outdoor Capitol Hill rally.

Those presidential contenders sought to rally their sides on the deeply divisive issue as Congress took up President Barack Obama's accord to curb Iran's nuclear ambition while easing sanctions -- a deal that its Senate opponents do not have enough votes to block.

Trump, who has said he couldn't scrap the deal as president but would stringently enforce it, said, "Never, ever, ever in my life have I seen any deal so incompetently negotiated."

Sarah Palin, who was John McCain's running mate in the 2008 presidential race, called the deal "insane" and a betrayal of the United States and Israel. She charged Clinton had flipped positions on negotiating with Iran, saying, "She spins faster than any of the Iranian centrifuges."

The pointed, often angry rhetoric at the rally at the Capitol by the 50 speakers contrasted sharply with the detailed policy speech in support of the deal that Clinton delivered at the Brookings Institution.

"I support it as part of a larger strategy toward Iran," said Clinton, who said she conducted back-channel talks with Iran through Oman and built international support for sanctions while secretary of state.

But she added, "We need to be clear-eyed about what we can expect from Iran. . . . And we shouldn't expect that this deal will lead to a broader changer in their behavior."

She offered a five-point strategy to deal with an Iran regime that she said cannot be trusted. It includes bolstering Israel's defenses and creating a regional coalition to curb Iran's dangerous behavior and proxies, Hamas and Hezbollah.

To deal opponents Sen. Chuck Schumer (D-N.Y.) and Israel, Clinton said, "I would not support this agreement for one second if this deal created danger for Israel."

She rejected criticism of the pact, dismissing as "unrealistic" demands to return to the table for a better deal and many GOP presidential candidates' vows to "tear up" the agreement if they won office.

But those steps are what was demanded at the Capitol Hill rally by speaker after speaker, many of them noting the prediction of Iran's supreme leader, Ayatollah Ali Khamenei, of Israel's demise in 25 years.

Trump said that the ayatollah also said Iran won't have anything to do with the United States once the deal is done.

"They rip us off, they take our money, they try to make us look like fools," Trump said. "We are led by very, very stupid people."

Cruz and many other speakers insisted that Senate Majority Leader Mitch McConnell (R-Ky.) and House Speaker John Boehner (R-Ohio) had the power to force a vote to block the deal in both chambers.

The rally, and a revolt by House Republicans, forced Boehner to revise plans for a vote on the deal.

In his speech to the rally, Rep. Lee Zeldin (R-Shirley) said, "The president says this deal is not built on trust -- it's built on verification. How can anyone support a deal built on verification if you don't know what the verification is?"

He said the 60-day period in a law for congressional review of the deal hasn't begun because Obama hasn't handed over side deals between Iran and international inspectors. "By law, no verification, no review period. No review period, no lifting of sanctions," he said.